Semiconductor superlattice electron wave interference filters

Abstract

The quantitative analogies that have been established between electron wave propagation in semiconductors and optical wave propagation in dielectrics are used to demonstrate that high-resolution energy filters in semiconductors are possible. An example filter consisting of electron quarter-wavelength layers of GaAs and Ga0.55Al0.45As and a half-wavelength layer of GaAs is presented and theoretically analyzed. The pass electron energy is 0.139 eV and the passband is only 0.003 eV (2.2% of pass energy). Such a filter could be incorporated into semiconductor devices (e.g., as a hot-electron emitter in a ballistic transistor) or used to control free-space electron beams (e.g., in electron beam lithography).